Although chemical industries based on petroleum have been remarkably developed from the mid-20th century onwards, prices of petroleum, gas and coal, which are typical examples of fossil fuel, are continuously increasing due to limitations of the resources thereof, and competition among countries has intensified in order to efficiently secure them. Also, chemical products produced from fossil fuel generate large amounts of byproducts in the manufacturing process, such as waste and gases that contribute to global warming, undesirably contributing to a serious environmental crisis that may affect all mankind, and rapidly shrinking conventional chemical industries. Thus, it is required to develop novel eco-friendly biochemical processes using biomass, which may be applied instead of chemical processes based on fossil fuel.
Biomass commonly refers to a vegetable source such as corn, bean, flaxseed, rapeseed, sugarcane, and palm oil, but typically may include living organics, or metabolic byproducts of materials constituting any one part of a carbon cycle.
However, existing biomass conversion techniques are limited in terms of competition with conventional chemical/petroleum products based on crude oil, due to restrictions of feeds/location conditions, low yields, high production costs, limits of the product spectrum, etc.
Also, anaerobic fermentation is easily carried out, exhibits high yield, and enables treatment of a wide range of biomass and organic waste, including land-sea biomass such as wood, seaweeds, etc., agricultural waste such as food waste, sewage sludge, corn stalks, millet stalks, animal excretions, etc., and palm waste, but there are no high-value raising methods other than biogases.
Furthermore, research into production of alcohols or fuel hydrocarbons from an organic acid mixture obtained via anaerobic fermentation is ongoing recently, but such processes are complicated and various products cannot be selectively produced.